Player-piano mechanism.



A. G. & C GULBRANSEN.

PLAYER PIANO MECHANISM.

APPLICATION men on. I5, 19M.

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A. G. a C. GULBRANSEN.

PLAYER PIANO MECHANISM.

APPLICATION HLEn' OCT. 15. I914.

Patented Aug. 6, 1918.

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v IT T T NT OFFIGE.

AXEL G. GULBRANSEN AND CHRISTIAN GULBRANSEN, or CHICAGO, ILL NOIS, ASSIGN- ons TO GULBRANSEN-DICKINSON COMPANY, on CHICAGO, ILLINOIS,A CORPORATION on ILLINOIS.

To all whom it may concern:

Be it known that we, AxnL G. GULBRAN- sn vanfd CHRISTIAN GULBRANSEN, bOl'/l10ltl zens of the Unlted States, reslding at Chi cago,,1n the county of Gook'and State of Illinois, have invented certain new and useful Improvements in Player-Piano Mechanism, of which the following is afull, clear,

concise, and exact description, reference being had to the accompanying drawings,

forming apartof this specification.

()ur 1nvent1on relates to automatlc playing pianos and is particularly concerned with those which are operated, or at least controlled, by pneumatic means 7 In devices of this kind, it is the general practice to provide a s0-called operating pneumatic for each striking rod in the piano andto control the operation of'said striking pneumatic by means of valves which, in turn, are moved by the admission of'air to respective diaphragm chambers, this admission of air to these diaphragm chambers being controlled by a so-called note-sheet traveling over a so-called tracker-board,'

the trackerboard having an opening foreach note adapted to be covered and uncovered according to the formation of the note-sheet.

As thenote-sheet travels from one side to the other of the tracker-board, it is, of course, necessary that it should tr ack' properly-that is, the note-sheet and the variouslyjdisposcd openingsthereinmust reg- I ister properly at all times w1th the regularly arranged openings in the tracker-iboard. It is the object of our inventlon to prov de automatlc means for constantly malntannng We are aware that so-called automatic tracking devices are old in the art, but our invention provides new and useful features which remedy defects in the automatic tracking devices of theprior art and which work toward the'end of, simple, reliable and efiicient operation. I r j 7 Most of 'the automatic tracking devices of the prior art are operated by pneumatic means controlled from the edge of the note-' sheet, but this is subject to certain inherent defects, due to the fact that shrinking and warping of the note-sheet is most pronounced at the edge and due to the fact that the edge is not always out absolutely PLAYER-PIANO MECHANISM.

Specification of Letters Patent.

Patented Aug. 6; 1918. Application filed October 15, 1914. Serial No. 866,752.

true, so that an automatic tracking device frequently does more harm than good. Our

of openings in the note-sheet, these open ngs 'belng' specially and. accurately cut. While 1t lspossible to utilize our invention the note-sheet for the exclusive function of. operating the automatic tracking device, it is a special feature of our invention that the arrangement is such that the automatic tracking device maybe Controlled byjthe note openings themselves, preferably the center ones, and thus no special note-sheet In th1s connection, our device large number of parts or of a complicated arrangement. 7 a I accompanying drawings, Figure 1 illustrates an elevational view Referring to the of an automatic playing piano, embodying the features of our invention;

Fig. 2 is a view, on a larger scale,"of the roller box and the mechanism for shifting the trackerboard;

is atop V f the Parts shQwl 'iu V Fig. .4; is. an enlarged view of th tracker? board and the music sheet. a

Referring first to'Fig. l,it will beseen that we provide, within the usual piano caslng 5, the usual pneumatlc action 6, which i invention is ofvthe type in which the automatic tracklng device is operated by means by providing a special series of openings in v is located directly in front of all the striker bars (not shown) and which comprises a plurality of operating-pneumatics, one for each striker bar. The details of this action I do not form part of the present invention and we have not, therefore, shownthis mechanism in detail.

The: instrument is operated by the creation of vacuum or partial. vacuum, and the mechanism for performing this function is found in the pumpers 7 7 ,which are, op-

erated by the pedals 8, 8. These parts mamtain a constant-low-pressure 1n the vacuum chamber'9,'froin which a tube 9 leads tothe wind-chest'of the pneumatic action 6, as

indicated The roller box 10 is mounted I l the trackerboard 17. The trackerboard is upon a shelf 11 and the tracker-board 17 referred to more fully later) is mounted approximately in the middle of this roller boX,

asshown in further detail in Fig. 2. The,

sprocket splined upon the motor shaft 12" of the motor 12, said shaft also having splined thereon a pinion 12, which, when in one position, meshes with a gear12 carried upon the shaft 13, and thus the music sheet is wound upon the roll 13.

A swinging arm 13 is pivoted at 13 which arm, when swung, to its alternate position reverses the direction of rotation of the rolls. This arm 13 engages a clutch member between the pinion 12 and the sprocket on the motor shaft, and when said arm is rotated about its pivot the pinion 12 will be disengaged from the gear 12 and the clutch will thereupon engage the sprocket and the music sheet will thus be rewound upon the roll 12 after the music has been played.

As is shown particularly in Fig. 2., the music sheet 14 is provided with a plurality of openings 15, which are adapted to register with a plurality of openings 16 in of the tracker relative to the box. One end of' the trackerboard has secured thereto a rod 20, which has pivoted thereto a link 21, which in turn is pivoted at 22 to a' bracket 23 secured to the movable board of the bellows 24. This bellows board is connected by means of a link 25 with the m'ovableboard of a'similar bellows 26, both boards being hinged to a stationary part 27. A channel 28' communicates with the bellows 26 and leads to a compartment 29 which is normally connected to atmosphere through the opening 30. This opening is adapted to be closed by a valve 31, secured to .a stem 32, the lower end of which is engaged by a diaphragm 33 covering a diaphragm chamber 34.

by means of the tube 37; The bellows 24 communicates, by means of the channel 38 A bleeder opening 35' connects with the dia sage from this chamber to the suction chamber36. It will thus be seen that, since the tube 37 communicates with the vacuum .chamber of the pneumatic action, there will be a partial vacuum in the chambers 34, 36

i and 43.

Referring again to the trackerboard, and particularly to Fig. 4, it will be observed that we have provided two sets of narrow slots 45 and 46, on either side of the center line passing between the two central openings in the trackerboard, The slots 45 communicate with a chamber 47, the rear of which is closed by a plate-48. Thischamber comniunicates,by means of a tube 49, with the diaphragm chamber 34. The slots 46 communicatewith a chamber 50, which is also closed by theplate 48, and this chamber communicates with the diaphragm chamber 43 by means of thetube 51. It will thus be understood that, when the slots 45 and 46 are not exposed to atmospheric pressure, the air pressure will be reduced in the chambers 47 and 50 and tubes 49 and 51. It will be observed from Fig. 4 that the openings 16 are slightly wider than the openings 15 in the music sheet and that the narrow slots 45,

' on the right of the center line, are disposed in position just inside the right hand margin of corresponding player openings 16, while the slots 46, on the left of the center line, are disposed just inside the left'hand margin of corresponding player openings 16.

In order to secure the proper tonal effects, it'is desirable that the openings in theimusic sheet pass directly over the openings in the tracker bar in 'order to operate the playing mechanism, but it has been found in practice, however, that the music sheet will shift from. one side to the other, and therebydestroy to some extent the proper tonal effect. By our invention, the 'music sheet is moved to its normal position when for any reason it has been shifted out of its proper course. Assuming, as the music sheet is being drawn from the music roll 12 by the unwinding roll 13, that the paper 14 has shifted so that one of the openings 15' takes a position shown in dotted lines at 52, it will be clearthat one of the slots 46 will thereupon be exposed so that the air will rush through the same and through the tube'51 into the diaphragm chamber 43. This will cause the diaphragm 43 to be raised and, consequently, the valve 41 will close the opening 40, whereupon the bellows 34 will be in direct communication with the suction means and this bellows. will then collapse, or partly collapse, so as to vcause the'trackerboard 17 to shift toward exposed to atmosphere and the bellows 26 will be'coll'apsed, owing to the diaphragm 33 being raised, when the bellows will be in communication with the suction means so as to exhaust the air from said bellows and cause a shifting of the tracker-board 17- toward the right until the slot or slots are covered by the music sheet as it travels across the tracker-board. The movement of the trackerboard to the right may be limited,'as by means of a screw 53.

After the openings have been closed by the paper, the valve 31 or 41 (whichever the case may be) willbe restored owing to the fact that the air' pressure will be reduced in the compartment 34: or 43 and also'in the corresponding tube, thus permitting air at atmospheric pressure to enter the bellows.

By this arrangement it will be clear that the openings in the music sheet 14 are always kept in proper registration with the openings in the trackerboard.

After the music has been played and the music sheet has been rewound upon the roller 12 by the mechanism previously de scribed, said roller is removed by pushing {hi6 spring pressed spindle 14 toward the We claim as new and desire to secure Letters Patent:

1. In a player piano, the combination of openings arranged on opposite sides of the I center thereof, each set being exclusive to its own side and being connected to a common chamber in the trackerboard and each chamber being eonnectedto said suction means,

said openings being entirely covered when said music sheet is tracking properly, valves operable when said openings are exposed to place either of said-bellows in communication with said suction means, and means connected with said bellows for securing a relative adjustment between, said music sheet and said trackerboard when the auxiliary openings are exposed to atmosphere.

2. In a player piano, the combination of suction means, a trackerboard, a music roll and an unwinding roll, said rolls and said tracker-board having movement relative to each other, controlling bellows for securing said movement normally open to the atmosphere, a diaphragm chamber for each bellows, a valve for each diaphragm chamber,

said trackerboard having two sets of auxiliary openings normally entirely covered by said music sheet and arranged on opposite sides of the center thereof, each set of openings being exclusive to itsown side and being connected to a common chamber in thetracker whiclrin turn is connected to one diaphragnrchamber, and means connecting the diaphragm' chambers withthe suction means, said controlling bellows serving to secure said movement in either direction in accordance with the exposure of either set of said auxiliary openingsto atmospheric pressure.

Y 3. In a player'piano, the combination of suction means, a movable trackerboard, amuslc roll and anunwinding roll, a pair of shifting bellows normally open to the atmosphere, a dlaphragm chamber for each bellows a valve for each (1121 hra m chamber said trackerboard having two sets of aux iliary openings normally entirely covered by said music sheet and arranged on opposite sides of the center thereof, each set of open'--'- ings being exclusive to its own side-and being connected to one diaphragmchamher, and means connecting the diaphragmchambers with the suction means, said bellows being directly connected to said trackerboard to shift the trackerboa-rd in either one of both directions in accordance with the exposure of either set of auxiliary openings to atmospheric pressure.

4. In a player piano, the combination of suction mechanism, a movable trackerboard, a music roll and an unwinding roll, a music sheet, means for causing said sheet to travel over said trackerboard and from one .roll to the other, shifting bellows connected to said trackerboard, said bellows being connected and normally open to atmosphere, a diaphragm chamber associated with each bellows, a valve for each bellows controlling the air inlet thereto, said trackerboard having two sets of auxiliary openings, arranged on opposite sides of the center of the trackerboard, each set being exclusive to its own side and being connected to one diaphragm chamber and being arranged to be exposed through the player openings of the note sheet only when the note sheet shifts, said diaphragm chambers having a common connection to the suction mechanism, and a device for limiting the movement of said trackerboard in one direction.

5. Ina player piano, a music roll, a movable trackerboard, a music sheet, means for drawing said music sheet across said trackerboard, said trackerboard having narrow auxiliary openings, positioned in vertical alinement with and just inside the margin of corresponding tracker openings and normally entirely covered by the music sheet,

said devices serving to shift said trackerboard when the music sheet exposes said auxiliary openings to the atmosphere.

($111 a player piano, a longitudinally movable tr-ackerboard, a music sheet, means for drawing said music sheet over said trackerboard, said trackerboard being provided with two sets of narrow auxiliary openings normally entirely covered by the music sheet, one set being on each side of the center of the tracker and positioned in vertical alinement with and just inside the margin of corresponding tracker openings, suction means connected with said auxiliary open ings, and mechanism interposed between said. suction means and trackerboard for shifting said trackerboard when the auxiliary' openings are exposed to the atmosphere.

,7. In a player piano, the combination of suction means, a tracker-board, a music roll and an unwinding roll, a perforated music sheet passing between said rolls and over said tracker-board, said rolls and said trackerboard having relative shifting movement therebetweema pair of bellows adapted to effect said shifting movement, valves for connecting said bellows to said suction means, said tracker board having two sets of auxiliary openings normally. covered by 0 said music sheet when the same is correctly alined on said tracker bar, each of said sets of openings arranged along different sec tions of said trackerboard and connected to separate chambers in said'trackerboard, the openingsvin one of said sets being controlled by the left hand edges of the music sheet perforations passing overthe corresponding traokerboard section, the openings in the other of said sets being controlled by the right-hand edges of the music sheet perforations passing over that corresponding trackerboard section, and pneumatic connections between said chambers and said valves for operating the latter when either of said sets of openings is exposed to atmospheric pressure. V

In witness whereof, we hereunto subscribe our names this 6th day of October, 1914.

, AXEL G. GULBRANSEN.

'CHRISTIAN GULBRANSEN,

Witnesses for both:

LEONARD W. NOVANDER, ERNEST W. RAPALEE.

Copies of this patent may be obtained for five cents each, ,by addressing the Commissioner of Patents,

Washington, I). 0. 

